280 THE CLAYS OF ARKANSAS. 
The geologic strata of the county belong to two distinct periods. 
The bottom lands are all alluvial sands, which are now being formed 
by the present streams. The prairie lands and ridges belong to a 
much earlier period in Quaternary time. 
Where the railroad passes up to Nubbin Ridge from the bottom 
land just south of Colona the cut shows the following section: 
Section of Nubbin Ridt/e near Colona. ^ . 
J Ft. in. 
Soil 10 
Reddish to yellowish-tinted loamy clay, containing buckshot 
concretions; practically impervious to water 2 2| 
White sandy clay, sharply separated from the above, by its lack 
of moisture, and grading down into a reddish resistant sand, 
and this to a purple loose sand 10 
The same order of strata that is given above is seen in the road 
a short distance west of Powell. 
The typical prairie lands in the western part of St. Francis County 
extend westward into Woodruff County. The following section was 
obtained in wells at Hunter: 
Section of wells at Hunter. 
Ft. in. 
Soil (a few inches) at top. 
Red clay, sticky and soft when wet 2 f> 
White clay 3-6 
Hardpan (clay) 9-15 
Clay and yellow sand, very hard when dry 5 
Fine gray sand 5 
White sand 4 
Quicksand with some gravel, water bearing 3 
Hardpan 3 
Saml becoming coarser at bottom, water bearing 35-45 
CLAY INDUSTRY. 
At present there is but one plant in Woodruff County where clay 
is utilized. This is a common wet-mud brick plant located at Cotton 
Plant. The bricks are made from the yellow loam which occurs in 
the prairie section of the county. There are no large towns in the 
county except Augusta, which is located in the alluvial sands of 
White River, so that the local demand for building brick is not greats 
YELL COUNTY. 
GENERAL GEOLOGY. 
The general geology of Yell County is similar to that of Pope and 
Logan on the north and to that of Scott and Logan on the west. 
The clays therefore fall naturally into the same classes, namely, 
(1) Carboniferous shales and clays interbedded with the hard rocks 
in place; (2) brick loam and buckshot clays; (3) terrace clays along 
Arkansas River; (4) clays of the Arkansas River flood plains. 
